C#

private void toolStripButton2_Click(object sender, EventArgs e)
{

    StreamWriter sw = new StreamWriter(@"C:\nefz.csv", false);
    DataTable dt = m_dtCallCentre;
    int iColCount = dt.Columns.Count;
    for (int i = 0; i < iColCount; i++)
    {
        sw.Write(dt.Columns[i]);
        if (i < iColCount - 1)
        {
            sw.Write(";");
        }
    }
    sw.Write(sw.NewLine);
    foreach (DataRow dr in dt.Rows)
    {
        for (int i = 0; i < iColCount; i++)
        {
            if (!Convert.IsDBNull(dr[i]))
            {
                sw.Write(dr[i].ToString());
            }
            if (i < iColCount - 1)
            {
                sw.Write(";");
            }
        }
        sw.Write(sw.NewLine);
    }
    sw.Close();

}